The present invention relates to color filters, and more particularly, to color filters having vertical stripes for use with cameras having an array of discrete sensors, such as CCD (charge coupled device) cameras.
As was pointed out in prior patent application Ser. No. 094,285, filed Nov. 19, 1979, now U.S. Pat. No. 4,288,812, in the name of R. Rhodes (RCA 74,184), a conventional vertical stripe color filter when placed in front of the CCD camera limits the bandwidth of the luminance signal to two-thirds of that determined by the Nyquist limit, which in turn is determined by the number of photosensors in a horizontal row of the CCD. In particular, if there are 320 photosensitive elements per horizontal line in the CCD, 320 sensors are scanned in 53 microseconds for a theoretical bandwidth of about 3 mHz. In the presence of a vertical stripe filter, the bandwidth is actually limited to about 2 mHz for the reasons as set forth in said prior application.
It is therefore desirable to have a color encoding filter for use with a CCD pickup device having a plurality of photosensitive elements which results a wider usable frequency response in the resulting luminance signal.